Nuclear Chemistry

Chemical Reactions

atoms attain stability by losing, gaining, or sharing electrons

Nuclear Reactions

atoms attain stability through changes in the nucleus

Radioactivity

the process by which an unstable nucleus spontaneously emits high energy particles or rays from the nucleus in order to attain a more stable nuclear state; process is called radioactive decay

Radioisotope

an isotope that contains an unstable nucleus

Strong Nuclear Force

an attractive force that binds protons and neutrons together in the nucleus; also called Strong Force; the strongest of the four fundamental forces

Band of Stability

the relationship between the nuclear force and the electrostatic forces between protons

Alpha Radiation

type of radiation; penetration is low; skin and paper can protect you; danger is low

Beta Radiation

type of radiation; penetration is medium; glass, clothing, and wood can protect you; danger is medium

Gamma Radiation

type of radiation; penetration is high; lead can protect you; danger is high

Positron Emission

a particle that has the same mass as an electron, but an opposite charge

K-Capture

sometimes, a nucleus will "capture" an electron from the inner most energy level. A proton plus an electron will form a neutron.

Half-Life

the time required for one half of the atoms in a radioactive isotope to decay

Decay Series

a series of radioactive isotopes produced by successive radioactive decay until a stable isotope is reached

Artificial Transmutation

bombardment of nuclei with charged and uncharged particles; used to produce transuranium elements

Transuranium Elements

Elements beyond uranium

Bombardment Reactions

man made reactions; induced by accelerating a particle and colliding it with a nuclide

Nuclear Fission

the reaction carried out in nuclear reactors; a very heavy nucleus splits into more stable nuclei releasing enormous amounts of energy

Chain Reaction

Self-propagating reaction - the material that starts the reaction is also one of the products of the reaction, and can start another reaction

Critical Mass

mass required to sustain a chain reaction

Nuclear Reactors

controlled-fission chain reactions to produce energy and radioactive nuclides

Atomic Bomb

Fission develops into an uncontrolled chain reaction

Nuclear Fusion

combining two light nuclei to form a heavier, more stable nucleus; would be the superior method of generating power since the products are not radioactive. However, the material must be in the plasma state which requires it to be about 6 times hotter than the sun's core!; reaction that fuels the Sun

Nebula

A giant cloud of gas and dust made mostly of hydrogen and helium

Protostar

Parts of the nebula begin to collapse and become denser. These clumps start heating up, but it is still not a star until nuclear fusion begins in the core.

Main Sequence Star

The moment that temperatures get hot enough for nuclear fusion a star is born. This is the longest stage of a star's life and is spent fusing hydrogen into helium. A star leaves the main sequence when it runs out of hydrogen. High mass stars use up their hydrogen faster than low mass stars.

Red Giant

When low mass stars run out hydrogen, gravity starts to win. The star shrinks until the center becomes hot enough to fuse helium into carbon. The star then grows 10x bigger and glows red.

Red Super Giant

Same as red giants, but bigger to begin with. They become some of the biggest stars in the universe. The core is so hot and dense that it will fuse elements all the way up to iron.

Planetary Nebula

Pressure eventually wins over gravity and the outer layers of the star get puffed away from the core in beautiful patterns. The leftover core eventually becomes a white dwarf.

White Dwarf

Gravity condenses the leftover core of a planetary nebula until it is very dense and about the size of Earth. There is no nuclear fusion, so it will eventually burn out and grow cold over billions of years.

Supernova

Nuclear fusion stops after a star fuses up to iron in its core. Without pressure from fusion to balance gravity the stars collapses and then explodes, creating all of the elements heavier than iron.

Neutron Star/Pulsar

Leftover remnants of large exploded stars. They are very small but very dense. They often spin and shoot energy into space. When they do this it is called a pulsar.

Black hole

An object with such strong gravitational force that not even light can escape it. Black holes are only created when the most massive of stars explode.

Recycled stardust

Matter from exploded and stars and planetary nebulas gets reused in the universe. New stars forming in areas with a lot of recycled stardust have a higher chance of forming with planets around them